As a technology for controlling a speed of a vehicle such as a car, for example, a safety device described in JP 2003-137001 A is known. The safety device detects that the vehicle is located at a position which departs from a road on the basis of map data of a navigation device and information indicative of the current position of the vehicle. When it is determined that an accelerator is manipulated so as to increase a driving speed of the vehicle and that the driving speed of the vehicle is higher than a predetermined value, the throttle is controlled so as to decrease the driving speed regardless of the manipulation of the accelerator.
JP 2003-137001 A intends to prevent the acceleration of the vehicle which the driver does not intend, even if the accelerator is erroneously manipulated.
In this situation, a technical problem is a determination of whether or not the manipulation of the accelerator is the erroneous manipulation. Then, in JP 2003-137001 A, it is determined that a pressing manipulation of the accelerator may be erroneous manipulation of the accelerator on the basis of the map information, when the vehicle is located at a position which departs from the road and the driving speed of the vehicle is detected as being higher than the predetermined value, and the above-mentioned condition is used as a condition to activate throttle suppression.
However, when the above-mentioned activation condition is used, the throttle suppression is activated when the vehicle only departs from the road to enter a parking space, and thus the drive performance in the parking space degrades.